Lubrication oil compositions

ABSTRACT

This invention relates to lubrication oil compositions comprising (i) a base fluid stock comprising (a) a PO3G fluid (a polytrimethylene ether glycol that is a fluid at ambient temperature) and (b) a PO3G ester fluid (an ester of a polytrimethylene ether glycol that is a fluid at ambient temperature), and (ii) one or more fuel oil additives.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to commonly owned U.S. application Ser. No.11/593,954, filed Nov. 7, 2006, entitled “POLYTRIMETHYLENE ETHER GLYCOLESTERS”; commonly owned U.S. Provisional Application Ser. No. 60/957,728filed concurrently herewith, entitled “LUBRICATION OIL COMPOSITIONS”;commonly owned U.S. Provisional Application Ser. No. 60/957,716, filedconcurrently herewith, entitled “LUBRICATION OIL COMPOSITIONS”; andcommonly owned U.S. Provisional Application Ser. No. 60/957722, filedconcurrently herewith, entitled “LUBRICATION OIL COMPOSITIONS”.

FIELD OF THE INVENTION

This invention relates compositions comprising (i) a polytrimethyleneether glycol and (ii) an acid ester (monoester and/or diester) ofpolytrimethylene ether glycol, and the use of such compositions aslubrication oils.

BACKGROUND

Certain mono- and diesters of polytrimethylene ether glycol (“PO3Gesters”) have properties that make them useful in a variety of fields,including as lubricants, as disclosed in commonly owned U.S. applicationSer. No. 11/593,954, filed Nov. 7, 2006, entitled “POLYTRIMETHYLENEETHER GLYCOL ESTERS”.

The present invention is directed to specific lubricant compositionsbased on combinations of such PO3G esters with polytrimethylene etherglycol (PO3G).

SUMMARY OF THE INVENTION

In one embodiment, the present invention relates to the use of mixturesof one or more PO3Gs and one or more PO3G esters, along with one or moreadditives, as a lubrication oils. The present invention thus provides alubrication oil composition comprising (i) a base fluid stock comprisinga mixture of (a) a PO3G fluid (a polytrimethylene ether glycol that is afluid at ambient temperature) and (b) a PO3G ester fluid (an ester of apolytrimethylene ether glycol that is a fluid at ambient temperature),and (ii) one or more lube oil additives.

When the PO3G and PO3G ester are based on biologically produced1,3-propanediol, lubricant compositions with a very high renewablecontent can be provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. In case of conflict, thepresent specification, including definitions, will control.

Except where expressly noted, trademarks are shown in upper case.

Unless stated otherwise, all percentages, parts, ratios, etc., are byweight.

When an amount, concentration, or other value or parameter is given aseither a range, preferred range or a list of upper preferable values andlower preferable values, this is to be understood as specificallydisclosing all ranges formed from any pair of any upper range limit orpreferred value and any lower range limit or preferred value, regardlessof whether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the invention be limitedto the specific values recited when defining a range.

When the term “about” is used in describing a value or an end-point of arange, the disclosure should be understood to include the specific valueor end-point referred to.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Use of “a” or “an” are employed to describe elements and components ofthe invention. This is done merely for convenience and to give a generalsense of the invention. This description should be read to include oneor at least one and the singular also includes the plural unless it isobvious that it is meant otherwise.

The materials, methods, and examples herein are illustrative only and,except as specifically stated, are not intended to be limiting. Althoughmethods and materials similar or equivalent to those described hereincan be used in the practice or testing of the present invention,suitable methods and materials are described herein.

Base Fluid Stock

As indicated above, the base fluid stock for use in the lubrication oilcompositions of the present invention comprises a mixture of a PO3G anda PO3G ester that is a fluid at ambient temperature (25° C.). The basefluid stock may also comprise other natural and/or synthetic fluidco-lubricants.

Examples of natural fluid co-lubricants include vegetable oil-basedlubricants, which are generally derived from plants and are generallycomposed of triglycerides. Normally, these are liquid at roomtemperature. Although many different parts of plants may yield oil, inactual practice oil is generally extracted primarily from the seeds ofoilseed plants. These oils include both edible and inedible oils, andinclude, for example, high oleic sunflower oil, rapeseed oil, soybeanoil, castor oil and the like, as well as modified oils such as disclosedin U.S. Pat. No. 6,583,302 (fatty acid esters) and I. Malchev,“Plant-Oil-Based Lubricants” (available from the Department of PlantAgriculture, Ontario Agriculture College, University of Guelph, 50 StoneRoad W., Guelph, Ontario, Canada N1G 2W1).

Synthetic fluid co-lubricants (other than the PO3G and PO3G esters)include lubricating oils such as hydrocarbon oils such as polybutylenes,polypropylenes, propylene-isobutylene copolymers; polyoxyalkylene glycolpolymers (other than PO3G) and their derivatives such as ethylene oxideand propylene oxide copolymers; and esters of dicarboxylic acids with avariety of alcohols such as dibutyl adipate, di(2-ethylhexyl)sebacate,di-hexyl fumarate, dioctyl sebacate, diisoctyl azelate, diisodecylazelate, dioctyl phthalate, didecyl phthalate, and the 2-ethylhexyldiester of linoleic acid dimer.

Preferably, the base stock comprises a predominant amount of PO3G/PO3Gester mixture (greater than 50 wt % based on the weight of the basestock). In some embodiments, the base stock can comprise the PO3G/PO3Gester mixture in an amount of about 66 wt % or greater, or about 75 wt %or greater, or about 90 wt % or greater, or about 95 wt % or greater,based on the total weight of the base fluid stock. In some preferredembodiments, the base fluid stock comprises only (or substantially only)the PO3G/PO3G ester mixture.

In one embodiment, the weight ratio of PO3G/PO3G ester in the base fluidstock is greater than 1:1 (the PO3G being the predominant component), orabout 1.5:1 or greater, or about 2:1 or greater, or about 5:1 orgreater, or about 20:1 or greater. Also, the weight ratio is preferablyabout 25:1 or less, or about 20:1 or less, or about 10:1 or less.

In another embodiment, the weight ratio of PO3G ester/PO3G in the basefluid stock is greater than 1:1 (the PO3G ester being the predominantcomponent), or about 1.5:1 or greater, or about 2:1 or greater, or about5:1 or greater, or about 20:1 or greater. Also, the weight ratio ispreferably about 25:1 or less, or about 20:1 or less, or about 10:1 orless.

In yet another embodiment, the weight ratio of PO3G/PO3G ester in thebase fluid stock is about 1:1 (approximately equivalent weight amountsof the two components).

The lubrication oil composition preferably comprises the base oil stockin an amount of about 50 wt % or greater, based on the total weight ofthe lubrication oil composition. In various embodiments, the lubricationoil can comprise the base stock in an amount of about 75 wt % orgreater, or about 90 wt % or greater, or about 95 wt % or greater, basedon the total weight of the lubrication oil composition.

Mono- and Diesters of Polytrimethylene Ether Glycol

In some embodiments, the PO3G esters comprise one or more compounds ofthe formula (I):

wherein Q represents the residue of a polytrimethylene ether glycolafter abstraction of the hydroxyl groups, R₂ is H or R₃CO, and each ofR₁ and R₃ is individually a substituted or unsubstituted aromatic,saturated aliphatic, unsaturated aliphatic or cyclo-aliphatic organicgroup, containing 4 to 40 carbon atoms, preferably at least 6 carbonatoms, more preferably at least 8 carbon atoms. In some embodiments eachof R₁ and R₃ has 20 carbon atoms or fewer, and in some embodiments 10carbon atoms or fewer. In some preferred embodiments, each of R₁ and R₃has 8 carbon atoms.

PO3G esters are preferably prepared by polycondensation of hydroxylgroups-containing monomers (monomers containing 2 or more hydroxylgroups) predominantly comprising 1,3-propanediol to form a PO3G (asdisclosed in further detail below), followed by esterification with amonocarboxylic acid (or equivalent), as disclosed in U.S. applicationSer. No. 11/593,954, filed Nov. 7, 2006, entitled “POLY-TRIMETHYLENEETHER GLYCOL ESTERS”.

The PO3G ester thus prepared is a composition preferably comprising fromabout 50 to 100 wt %, more preferably from about 75 to 100 wt %, diesterand from 0 to about 50 wt %, more preferably from 0 to about 25 wt %,monoester, based on the total weight of the esters. Preferably the mono-and diesters are esters of 2-ethylhexanoic acid.

The PO3G used for preparing the ester need not be the same as the PO3Gco-component of the base fluid stock.

Polytrimethylene Ether Glycol (PO3G)

PO3G for the purposes of the present invention is an oligomeric orpolymeric ether glycol in which at least 50% of the repeating units aretrimethylene ether units. More preferably from about 75% to 100%, stillmore preferably from about 90% to 100%, and even more preferably fromabout 99% to 100%, of the repeating units are trimethylene ether units.

PO3G is preferably prepared by polycondensation of monomers comprising1,3-propanediol, preferably in the presence of an acid catalyst, thusresulting in polymers or copolymers containing —(CH₂CH₂CH₂O)— linkage(e.g, trimethylene ether repeating units). As indicated above, at least50% of the repeating units are trimethylene ether units.

When a sulfur-based acid catalyst is utilized (such as sulfuric acid) toprepare the PO3G, the resulting product preferably contains less thanabout 20 ppm, more preferably less than about 10 ppm, of sulfur.

In addition to the trimethylene ether units, lesser amounts of otherunits, such as other polyalkylene ether repeating units, may be present.In the context of this disclosure, the term “polytrimethylene etherglycol” encompasses PO3G made from essentially pure 1,3-propanediol, aswell as those oligomers and polymers (including those described below)containing up to about 50% by weight of comonomers.

The 1,3-propanediol employed for preparing the PO3G may be obtained byany of the various well known chemical routes or by biochemicaltransformation routes. Preferred routes are described in, for example,U.S. Pat. No. 5,015,789, U.S. Pat. No. 5,276,201, U.S. Pat. No.5,284,979, U.S. Pat. No. 5,334,778, U.S. Pat. No. 5,364,984, U.S. Pat.No. 5,364,987, U.S. Pat. No. 5,633,362, U.S. Pat. No. 5,686,276, U.S.Pat. No. 5,821,092, U.S. Pat. No. 5,962,745, U.S. Pat. No. 6,140,543,U.S. Pat. No. 6,232,511, U.S. Pat. No. 6,235,948, U.S. Pat. No.6,277,289, U.S. Pat. No. 6,297,408, U.S. Pat. No. 6,331,264, U.S. Pat.No. 6,342,646, U.S. Pat. No. 7,038,092, U.S. Pat. No. 7,084,311, U.S.Pat. No. 7,098,368, U.S. Pat. No. 7,009,082 and US20050069997A1.

Preferably, the 1,3-propanediol is obtained biochemically from arenewable source (“biologically-derived” 1,3-propanediol).

A particularly preferred source of 1,3-propanediol is via a fermentationprocess using a renewable biological source. As an illustrative exampleof a starting material from a renewable source, biochemical routes to1,3-propanediol (PDO) have been described that utilize feedstocksproduced from biological and renewable resources such as corn feedstock. For example, bacterial strains able to convert glycerol into1,3-propanediol are found in the species Klebsiella, Citrobacter,Clostridium, and Lactobacillus. The technique is disclosed in severalpublications, including U.S. Pat. No. 5,633,362, U.S. Pat. No. 5,686,276and U.S. Pat. No. 5,821,092. U.S. Pat. No. 5,821,092 discloses, interalia, a process for the biological production of 1,3-propanediol fromglycerol using recombinant organisms. The process incorporates E. colibacteria, transformed with a heterologous pdu diol dehydratase gene,having specificity for 1,2-propanediol. The transformed E. coli is grownin the presence of glycerol as a carbon source and 1,3-propanediol isisolated from the growth media. Since both bacteria and yeasts canconvert glucose (e.g., corn sugar) or other carbohydrates to glycerol,the processes disclosed in these publications provide a rapid,inexpensive and environmentally responsible source of 1,3-propanediolmonomer.

The biologically-derived 1,3-propanediol, such as produced by theprocesses described and referenced above, contains carbon from theatmospheric carbon dioxide incorporated by plants, which compose thefeedstock for the production of the 1,3-propanediol. In this way, thebiologically-derived 1,3-propanediol preferred for use in the context ofthe present invention contains only renewable carbon, and not fossilfuel-based or petroleum-based carbon. The PO3G and esters thereonutilizing the biologically-derived 1,3-propanediol, therefore, have lessimpact on the environment as the 1,3-propanediol used in thecompositions does not deplete diminishing fossil fuels and, upondegradation, releases carbon back to the atmosphere for use by plantsonce again. Thus, the compositions of the present invention can becharacterized as more natural and having less environmental impact thansimilar compositions comprising petroleum based glycols.

The biologically-derived 1,3-propanediol, PO3G and PO3G esters, may bedistinguished from similar compounds produced from a petrochemicalsource or from fossil fuel carbon by dual carbon-isotopic fingerprinting. This method usefully distinguishes chemically-identicalmaterials, and apportions carbon in the copolymer by source (andpossibly year) of growth of the biospheric (plant) component. Theisotopes, ¹⁴C and ¹³C, bring complementary information to this problem.The radiocarbon dating isotope (¹⁴C), with its nuclear half life of 5730years, clearly allows one to apportion specimen carbon between fossil(“dead”) and biospheric (“alive”) feedstocks (Currie, L. A. “SourceApportionment of Atmospheric Particles,” Characterization ofEnvironmental Particles, J. Buffle and H. P. van Leeuwen, Eds., 1 ofVol. I of the IUPAC Environmental Analytical Chemistry Series (LewisPublishers, Inc) (1992) 3-74). The basic assumption in radiocarbondating is that the constancy of ¹⁴C concentration in the atmosphereleads to the constancy of ¹⁴C in living organisms. When dealing with anisolated sample, the age of a sample can be deduced approximately by therelationship:

t=(−5730/0.693)In(A/A ₀)

wherein t=age, 5730 years is the half-life of radiocarbon, and A and A₀are the specific ¹⁴C activity of the sample and of the modern standard,respectively (Hsieh, Y., Soil Sci. Soc. Am J., 56, 460, (1992)).However, because of atmospheric nuclear testing since 1950 and theburning of fossil fuel since 1850, ¹⁴C has acquired a second,geo-chemical time characteristic. Its concentration in atmospheric CO₂,and hence in the living biosphere, approximately doubled at the peak ofnuclear testing, in the mid-1960s. It has since been gradually returningto the steady-state cosmogenic (atmospheric) baseline isotope rate(¹⁴C/¹²C) of ca. 1.2×10⁻¹², with an approximate relaxation “half-life”of 7-10 years. (This latter half-life must not be taken literally;rather, one must use the detailed atmospheric nuclear input/decayfunction to trace the variation of atmospheric and biospheric ¹⁴C sincethe onset of the nuclear age.) It is this latter biospheric ¹⁴C timecharacteristic that holds out the promise of annual dating of recentbiospheric carbon. ¹⁴C can be measured by accelerator mass spectrometry(AMS), with results given in units of “fraction of modern carbon”(f_(M)). f_(M) is defined by National Institute of Standards andTechnology (NIST) Standard Reference Materials (SRMs) 4990B and 4990C,known as oxalic acids standards HOxI and HOxII, respectively. Thefundamental definition relates to 0.95 times the ¹⁴C/¹²C isotope ratioHOxI (referenced to AD 1950). This is roughly equivalent todecay-corrected pre-Industrial Revolution wood. For the current livingbiosphere (plant material), f_(M)≈1.1.

The stable carbon isotope ratio (¹³C/¹²C) provides a complementary routeto source discrimination and apportionment. The ¹³C/¹²C ratio in a givenbiosourced material is a consequence of the ¹³C/¹²C ratio in atmosphericcarbon dioxide at the time the carbon dioxide is fixed and also reflectsthe precise metabolic pathway. Regional variations also occur.Petroleum, C₃ plants (the broadleaf), C₄ plants (the grasses), andmarine carbonates all show significant differences in ¹³C/¹²C and thecorresponding δ ¹³C values. Furthermore, lipid matter of C₃ and C₄plants analyze differently than materials derived from the carbohydratecomponents of the same plants as a consequence of the metabolic pathway.Within the precision of measurement, ¹³C shows large variations due toisotopic fractionation effects, the most significant of which for theinstant invention is the photosynthetic mechanism. The major cause ofdifferences in the carbon isotope ratio in plants is closely associatedwith differences in the pathway of photosynthetic carbon metabolism inthe plants, particularly the reaction occurring during the primarycarboxylation, i.e., the initial fixation of atmospheric CO₂. Two largeclasses of vegetation are those that incorporate the “C₃” (orCalvin-Benson) photosynthetic cycle and those that incorporate the “C₄”(or Hatch-Slack) photosynthetic cycle. C₃ plants, such as hardwoods andconifers, are dominant in the temperate climate zones. In C₃ plants, theprimary CO₂ fixation or carboxylation reaction involves the enzymeribulose-1,5-diphosphate carboxylase and the first stable product is a3-carbon compound. C₄ plants, on the other hand, include such plants astropical grasses, corn and sugar cane. In C₄ plants, an additionalcarboxylation reaction involving another enzyme, phosphenol-pyruvatecarboxylase, is the primary carboxylation reaction. The first stablecarbon compound is a 4-carbon acid, which is subsequentlydecarboxylated. The CO₂ thus released is refixed by the C₃ cycle.

Both C₄ and C₃ plants exhibit a range of ¹³C/¹²C isotopic ratios, buttypical values are ca. −10 to −14 per mil (C₄) and −21 to −26 per mil(C₃) (Weber et al., J. Agric. Food Chem., 45, 2942 (1997)). Coal andpetroleum fall generally in this latter range. The ¹³C measurement scalewas originally defined by a zero set by pee dee belemnite (PDB)limestone, where values are given in parts per thousand deviations fromthis material. The “δ¹³C” values are in parts per thousand (per mil),abbreviated %, and are calculated as follows:

${\delta^{13}C} \equiv {\frac{{\left( {}^{13}{C/^{12}C} \right){sample}} - {\left( {}^{13}{C/^{12}C} \right){standard}}}{\left( {}^{13}{C/^{12}C} \right){standard}} \times 1000\%}$

Since the PDB reference material (RM) has been exhausted, a series ofalternative RMs have been developed in cooperation with the IAEA, USGS,NIST, and other selected international isotope laboratories. Notationsfor the per mil deviations from PDB is δ¹³C. Measurements are made onCO₂ by high precision stable ratio mass spectrometry (IRMS) on molecularions of masses 44, 45 and 46.

Biologically-derived 1,3-propanediol, and compositions comprisingbiologically-derived 1,3-propanediol, therefore, may be completelydistinguished from their petro-chemical derived counterparts on thebasis of ¹⁴C (f_(M)) and dual carbon-isotopic finger-printing,indicating new compositions of matter. The ability to distinguish theseproducts is beneficial in tracking these materials in commerce. Forexample, products comprising both “new” and “old” carbon isotopeprofiles may be distinguished from products made only of “old”materials. Hence, the instant materials may be followed in commerce onthe basis of their unique profile and for the purposes of definingcompetition, for determining shelf life, and especially for assessingenvironmental impact.

Preferably the 1,3-propanediol used as the reactant or as a component ofthe reactant will have a purity of greater than about 99%, and morepreferably greater than about 99.9%, by weight as determined by gaschromatographic analysis. Particularly preferred are the purified1,3-propanediols as disclosed in U.S. Pat. No. 7,038,092, U.S. Pat. No.7,098,368, U.S. Pat. No. 7,084,311 and US20050069997A1, as well as PO3Gmade therefrom as disclosed in US20050020805A1.

The purified 1,3-propanediol preferably has the followingcharacteristics:

(1) an ultraviolet absorption at 220 nm of less than about 0.200, and at250 nm of less than about 0.075, and at 275 nm of less than about 0.075;and/or

(2) a composition having L*a*b* “b*” color value of less than about 0.15(ASTM D6290), and an absorbance at 270 nm of less than about 0.075;and/or

(3) a peroxide composition of less than about 10 ppm; and/or

(4) a concentration of total organic impurities (organic compounds otherthan 1,3-propanediol) of less than about 400 ppm, more preferably lessthan about 300 ppm, and still more preferably less than about 150 ppm,as measured by gas chromatography.

The starting material for making PO3G will depend on the desired PO3G,availability of starting materials, catalysts, equipment, etc., andcomprises “1,3-propanediol reactant.” By “1,3-propanediol reactant” ismeant 1,3-propanediol, and oligomers and prepolymers of 1,3-propanediolpreferably having a degree of polymerization of 2 to 9, and mixturesthereof. In some instances, it may be desirable to use up to 10% or moreof low molecular weight oligomers where they are available. Thus,preferably the starting material comprises 1,3-propanediol and the dimerand trimer thereof. A particularly preferred starting material iscomprised of about 90% by weight or more 1,3-propanediol, and morepreferably 99% by weight or more 1,3-propanediol, based on the weight ofthe 1,3-propanediol reactant.

PO3G can be made via a number of processes known in the art, such asdisclosed in U.S. Pat. No. 6,977,291 and U.S. Pat. No. 6,720,459. Thepreferred processes are as set forth in U.S. Pat. No. 7,074,969, U.S.Pat. No. 7,157,607, U.S. Pat. No. 7,161,045 and U.S. Pat. No. 7,164,046.

As indicated above, PO3G may contain lesser amounts of otherpolyalkylene ether repeating units in addition to the trimethylene etherunits. The monomers for use in preparing polytrimethylene ether glycolcan, therefore, contain up to 50% by weight (preferably about 20 wt % orless, more preferably about 10 wt % or less, and still more preferablyabout 2 wt % or less), of comonomer polyols in addition to the1,3-propanediol reactant. Comonomer polyols that are suitable for use inthe process include aliphatic diols, for example, ethylene glycol,1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol,1,10-decanediol, 1,12-dodecanediol,3,3,4,4,5,5-hexafluro-1,5-pentanediol,2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, and3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-hexadecafluoro-1,12-dodecanediol;cycloaliphatic diols, for example, 1,4-cyclohexanediol,1,4-cyclohexanedimethanol and isosorbide; and polyhydroxy compounds, forexample, glycerol, trimethylolpropane, and pentaerythritol. A preferredgroup of comonomer diols is selected from the group consisting ofethylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol,2,2-diethyl-1,3-propanediol, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol,C₆-C₁₀ diols (such as 1,6-hexanediol, 1,8-octanediol and1,10-decanediol) and isosorbide, and mixtures thereof. A particularlypreferred diol other than 1,3-propanediol is ethylene glycol, and C₆-C₁₀diols can be particularly useful as well.

One preferred PO3G containing comonomers is poly(trimethylene-ethyleneether)glycol such as described in US20040030095A1. Preferredpoly(trimethylene-ethylene ether)glycols are prepared by acid catalyzedpolycondensation of from 50 to about 99 mole % (preferably from about 60to about 98 mole %, and more preferably from about 70 to about 98 mole%) 1,3-propanediol and up to 50 to about 1 mole % (preferably from about40 to about 2 mole %, and more preferably from about 30 to about 2 mole%) ethylene glycol.

Preferably, the PO3G after purification has essentially no acid catalystend groups, but may contain very low levels of unsaturated end groups,predominately allyl end groups, in the range of from about 0.003 toabout 0.03 meq/g. Such a PO3G can be considered to comprise or consistessentially of the compounds having the following formulae (II) and(III):

HO—((CH₂)₃O)_(m)—H   (II)

HO—((CH₂)₃—O)_(m)CH₂CH═CH₂   (III)

wherein m is in a range such that the Mn (number average molecularweight) is within the range of from about 200 to about 10000, withcompounds of formula (III) being present in an amount such that theallyl end groups (preferably all unsaturation ends or end groups) arepresent in the range of from about 0.003 to about 0.03 meq/g.

The preferred PO3G for use in the invention has an Mn (number averagemolecular weight) of at least about 250, more preferably at least about1000, and still more preferably at least about 2000. The Mn ispreferably less than about 10000, more preferably less than about 5000,and still more preferably less than about 3500. Blends of PO3Gs can alsobe used. For example, the PO3G can comprise a blend of a higher and alower molecular weight PO3G, preferably wherein the higher molecularweight PO3G has a number average molecular weight of from about 1000 toabout 5000, and the lower molecular weight PO3G has a number averagemolecular weight of from about 200 to about 950. The Mn of the blendedPO3G will preferably still be in the ranges mentioned above.

PO3G preferred for use herein is typically polydisperse having apolydispersity (i.e. Mw/Mn) of preferably from about 1.0 to about 2.2,more preferably from about 1.2 to about 2.2, and still more preferablyfrom about 1.5 to about 2.1. The polydispersity can be adjusted by usingblends of PO3G.

PO3G for use in the present invention preferably has a color value ofless than about 100 APHA, and more preferably less than about 50 APHA,and a viscosity which is preferably greater than the viscosity of thePO3G ester. A preferred viscosity is about 100 cS or greater at 40° C.

Acid and Equivalents

The esterification of the PO3G is carried out by reaction with an acidand/or equivalent, preferably a monocarboxylic acid and/or equivalent.

By “monocarboxylic acid equivalent” is meant compounds that performsubstantially like monocarboxylic acids in reaction with polymericglycols and diols, as would be generally recognized by a person ofordinary skill in the relevant art. Monocarboxylic acid equivalents forthe purpose of the present invention include, for example, esters ofmonocarboxylic acids, and ester-forming derivatives such as acid halides(e.g., acid chlorides) and anhydrides.

Preferably, a monocarboxylic acid is used having the formula R—COOH,wherein R is a substituted or unsubstituted aromatic, aliphatic orcycloaliphatic organic moiety containing from 6 to 40 carbon atoms.

Mixtures of different monocarboxylic acids and/or equivalents are alsosuitable.

As indicated above, the monocarboxylic acid (or equivalent) can bearomatic, aliphatic or cycloaliphatic. In this regard, “aromatic”monocarboxylic acids are monocarboxylic acids in which a carboxyl groupis attached to a carbon atom in a benzene ring system such as thosementioned below. “Aliphatic” monocarboxylic acids are monocarboxylicacids in which a carboxyl group is attached to a fully saturated carbonatom or to a carbon atom which is part of an olefinic double bond. Ifthe carbon atom is in a ring, the equivalent is “cycloaliphatic.”

The monocarboxylic acid (or equivalent) can contain any substituentgroups or combinations thereof (such as functional groups like amide,amine, carbonyl, halide, hydroxyl, etc.), so long as the substituentgroups do not interfere with the esterification reaction or adverselyaffect the properties of the resulting ester product.

The monocarboxylic acids and equivalents can be from any source, butpreferably are derived from natural sources or are bio-derived.

The following acids and their derivatives are specifically preferred:lauric, myristic, palmitic, stearic, arachidic, benzoic, caprylic,erucic, palmitoleic, pentadecanoic, heptadecanoic, nonadecanoic,linoleic, arachidonic, oleic, valeric, caproic, capric and2-ethylhexanoic acids, and mixtures thereof. Particularly preferredacids or derivatives thereof are 2-ethylhexanoic acid, benzoic acid,stearic acid, lauric acid and oleic acid.

Esterification Process

For preparation of the esters, the PO3G can be contacted, preferably inthe presence of an inert gas, with the monocarboxylic acid(s) attemperatures ranging from about 100° C. to about 275° C., preferablyfrom about 125° C. to about 250° C. The process can be carried out atatmospheric pressure or under vacuum. During the contacting water isformed is formed and can be removed in the inert gas stream or undervacuum to drive the reaction to completion.

To facilitate the reaction of PO3G with carboxylic acid an esterficationcatalyst is generally used, preferably a mineral acid catalyst. Examplesof mineral acid catalysts include but are not restricted to sulfuricacid, hydrochloric acid, phosphoric acid, hydriodic acid, andheterogeneous catalysts such as zeolites, heteropolyacid, amberlyst, andion exchange resin. Preferred esterification acid catalysts are selectedfrom the group consisting of sulfuric acid, phosphoric acid,hydrochloric acid and hydroiodic acid. A particularly preferred mineralacid catalyst is sulfuric acid.

The amount of catalyst used can be from about 0.01 wt % to about 10 wt %of the reaction mixture, preferably from 0.1 wt % to about 5 wt %, andmore preferably from about 0.2 wt % to about 2 wt %, of the reactionmixture.

Any ratio of carboxylic acid, or derivatives thereof, to glycol hydroxylgroups can be used. The preferred ratio of acid to hydroxyl groups isfrom about 3:1 to about 1:2, where the ratio can be adjusted to shiftthe ratio of monoester to diester in the product. Generally to favorproduction of diesters slightly more than a 1:1 ratio is used. To favorproduction of monoesters, a 0.5:1 ratio or less of acid to hydroxyl isused.

A preferred method for esterification comprises polycondensing1,3-propanediol reactant to polytrimethylene ether glycol using amineral acid catalyst, then adding carboxylic acid and carrying out theesterification without isolating and purifying the PO3G. In this method,the etherification or polycondensation of 1,3-propanediol reactant toform polytrimethylene ether glycol is carried out using an acid catalystas disclosed in U.S. Pat. No. 6,977,291 and U.S. Pat. No. 6,720,459. Theetherification reaction may also be carried out using a polycondensationcatalyst that contains both an acid and a base as described inJP2004-182974A. The polycondensation or etherification reaction iscontinued until desired molecular weight is reached, and then thecalculated amount of monocarboxylic acid is added to the reactionmixture. The reaction is continued while the water byproduct is removed.At this stage both esterification and etherification reactions occursimultaneously. Thus, in this preferred esterification method the acidcatalyst used for polycondensation of diol is also used foresterification. If necessary additional esterification catalyst can beadded at the esterification stage.

In this procedure, the viscosity (molecular weight) of the resultingproduct is controlled by the point at which the carboxylic acid isadded.

In an alternative procedure, the esterification reaction can be carriedout on purified PO3G by addition of an esterification catalyst andcarboxylic acid followed by heating and removal of water. In thisprocedure, viscosity of the resulting product is predominantly afunction of the molecular weight of the PO3G utilized.

Regardless of which esterification procedure is followed, after theesterification step any by products are removed, and then the catalystresidues remaining from poly-condensation and/or esterification areremoved in order to obtain an ester product that is stable, particularlyat high temperatures. This may be accomplished by hydrolysis of thecrude ester product by treatment with water at about 80° C. to about100° C. for a time sufficient to hydrolyze any residual acid estersderived from the catalyst without impacting significantly the carboxylicacid esters. The time required can vary from about 1 to about 8 hours.If the hydrolysis is carried out under pressure, higher temperatures andcorrespondingly shorter times are possible. At this point the productmay contain diesters, monoesters, or a combination of diesters andmonoesters, and small amounts of acid catalyst, unreacted carboxylicacid and diol depending on the reaction conditions. The hydrolyzedpolymer is further purified to remove water, acid catalyst and unreactedcarboxylic acid by the known conventional techniques such as waterwashings, base neutralization, filtration and/or distillation. Unreacteddiol and acid catalyst can, for example, be removed by washing withdeionized water. Unreacted carboxylic acid also can be removed, forexample, by washing with deionized water or aqueous base solutions, orby vacuum stripping.

Hydrolysis is generally followed by one or more water washing steps toremove acid catalyst, and drying, preferably under vacuum, to obtain theester product. The water washing also serves to remove unreacted diol.Any unreacted monocarboxylic acid present may also be removed in thewater washing, but may also be removed by washing with aqueous base orby vacuum stripping.

If desired, the product can be fractionated further to isolate lowmolecular weight esters by a fractional distillation under reducedpressure.

Proton NMR and wavelength X-ray fluorescence spectroscopic methods canbe used to identify and quantify any residual catalyst (such as sulfur)present in the polymer. The proton NMR can, for example, identify thesulfate ester groups present in the polymer chain, and wavelength x-rayfluorescence method can determine the total sulfur (inorganic andorganic sulfur) present in the polymer. The esters of the invention madefrom the process described above are substantially sulfur free and thususeful for high temperature applications.

Preferably, the PO3G esters after purification have essentially no acidcatalyst end groups, but may contain very low levels of unsaturated endgroups, predominately allyl end groups, in the range of from about 0.003to about 0.03 meq/g. Such PO3G ester can be considered to comprise(consist essentially of) the compounds having the following formulae(IV) and (V):

R₁—C(O)—O—((CH₂)₃O)_(m)—R₂   (IV)

R₁—C(O)—O—((CH₂)₃—O)_(m)CH₂CH═CH₂   (V)

wherein R₂ is H or R₃C(O); each of R₁ and R₃ is individually asubstituted or unsubstituted aromatic, saturated aliphatic, unsaturatedaliphatic, or cycloaliphatic organic group containing from 6 to 40carbon atoms; m is in a range such that the Mn is within the range offrom about 200 to about 10000; and with compounds of formula (III) beingpresent in an amount such that the allyl end groups (preferably allunsaturation ends or end groups) are present in the range of from about0.003 to about 0.03 meq/g.

Preferably, the PO3G ester has a viscosity which is less than theviscosity of PO3G. Preferred viscosities of PO3G esters range from about20 cS to about 150 cS at 40° C., and more preferably are about 100 cS orless.

Other preferred properties of the PO3G esters can be determined basedupon the preferences stated above for PO3G in and of itself. Forexample, preferred molecular weights and polydispersities are based onthe preferred molecular weights and polydispersities of the PO3Gcomponent of the ester.

Additives

Synthetic lube oil compositions in accordance with the present inventioncomprise a mixture of the base stock and one or more additives, whereeach additive is employed for the purpose of improving the performanceand properties of the base stock in its intended application, e.g., as ahydraulic fluid, a gear oil, a brake fluid, a compressor lubricant, atextile and calender lubricant, a metalworking fluid, a refrigerationlubricant, a two-cycle engine lubricant and/or crankcase lubricant.

The additives can generally be added in amounts based on the type ofadditive and desired level of additive effect, which can generally bedetermined by those skilled in the relevant art.

Preferably the additives are miscible in either or both of the PO3G andPO3G esters.

Preferably, the lube oil additive(s) comprise at least one of ashlessdispersant, metal detergent, viscosity modifier, anti-wear agent,antioxidant, friction modifier, pour point depressant, anti-foamingagent, corrosion inhibitor, demulsifier, rust inhibitor and mixturesthereof.

When the lube oil composition is used as a refrigeration lubricant, thelube oil additive(s) preferably comprise at least one of extremepressure and antiwear additive, oxidation and thermal stabilityimprover, corrosion inhibitor, viscosity index improver, pour pointdepressant, floc point depressant, detergent, anti-foaming agent,viscosity adjuster and mixtures thereof.

It is intended to be within the scope of the present invention to useany one or more of the specified additives alone or in combination withone or more of the remaining specified additives. It is also within thescope of the present invention to use more than one of any specifiedadditive, e.g., one or more friction modifiers, either alone or incombination of one or more of the other specified additives, e.g., incombination with one or more corrosion inhibitors.

The individual additives may be incorporated into a base stock in anyconvenient way. Thus, each of the components can be added directly tothe base stock by dispersing or dissolving it in the base stock at thedesired level of concentration. Such blending may occur at ambienttemperature or at an elevated temperature.

Alternatively, all or some of the additives can be blended into aconcentrate or additive package that is subsequently blended into basestock to make finished lubricant. The concentrate will typically beformulated to contain the additive(s) in proper amounts to provide thedesired concentration in the formulation when the concentrate iscombined with a predetermined amount of base lubricant.

Non-limiting, illustrative examples of various additives follow.

The ashless dispersant comprises polymeric hydrocarbon backbone havingfunctional groups that are capable of associating with particles to bedispersed. Typically, the dispersants comprise amine, alcohol, amideand/or ester polar moieties attached to the polymer backbone often via abridging group. The ashless dispersant may be, for example, selectedfrom salts, esters, amino-esters, amides, imides and oxazolines of longchain hydrocarbon substituted mono- and dicarboxylic acids and/or theiranhydrides, thiocarboxylate derivatives of long chain hydrocarbons, longchain aliphatic hydrocarbons having a polyamine attached directlythereto, and Mannich condensation products formed by condensing a longchain substituted phenol with formaldehyde and polyalkylene polyamine.

The viscosity modifier (VM) functions to impart high and low temperatureoperability to a lubricating oil. The VM used may have that solefunction, or may be multifunctional.

Multifunctional viscosity modifiers that also function as dispersantsare also known. Illustrative viscosity modifiers are polyisobutylene,copolymers of ethylene and propylene and higher alpha-olefins,polymethacrylates, polyalkylmethacrylates, methacrylate copolymers,copolymers of an unsaturated dicarboxylic acid and a vinyl compound,inter polymers of styrene and acrylic esters, and partially hydrogenatedcopolymers of styrene/isoprene, styrene/butadiene, andisoprene/butadiene, as well as the partially hydrogenated homopolymersof butadiene and isoprene and isoprene/divinylbenzene.

Metal-containing or ash-forming detergents function both as detergentsto reduce or remove deposits and as acid neutralizers or rustinhibitors, thereby reducing wear and corrosion and extending enginelife. Detergents generally comprise a polar head with long hydrophobictail, with the polar head comprising a metal salt of an acid organiccompound. The salts may contain a substantially stoichiometric amount ofthe metal in which they are usually described as normal or neutralsalts, and would typically have a total base number (TBN), as may bemeasured by ASTM D-2896 of from 0 to about 80. It is possible to includelarge amounts of a metal base by reacting an excess of a metal compoundsuch as an oxide or hydroxide with an acid gas such as carbon dioxide.The resulting overbased detergent comprises neutralized detergent as theouter layer of a metal base (e.g., carbonate) micelle. Such overbaseddetergents may have a TBN of about 150 or greater, and typically fromabout 250 to about 450 or more.

Illustrative detergents include neutral and overbased sulfonates,phenates, sulfurized phenates, thiophosphonates, salicylates, andnaphthenates and other oil-soluble carboxylates of a metal, particularlythe alkali or alkaline earth metals, e.g., sodium, potassium, lithium,calcium, and magnesium. The most commonly used metals are calcium andmagnesium, which may both be present in detergents used in a lubricant,and mixtures of calcium and/or magnesium with sodium. Particularlyconvenient metal detergents are neutral and overbased calcium sulfonateshaving TBN of from about 20 to about 450, and neutral and overbasedcalcium phenates and sulfurized phenates having TBN of from about 50 toabout 450.

Dihydrocarbyl dithiophosphate metal salts are frequently used asanti-wear and antioxidant agents. The metal may be an alkali or alkalineearth metal, or aluminum, lead, tin, molybdenum, manganese, nickel orcopper. The zinc salts are most commonly used in lubricating oil inamounts of from about 0.1 to about 10 wt %, preferably from about 0.2 toabout 2 wt %, based upon the total weight of the lubricating oilcomposition. They may be prepared in accordance with known techniques byfirst forming a dihydrocarbyl dithiophosphoric acid (DDPA), usually byreaction of one or more alcohol or a phenol with P₂S₅ and thenneutralizing the formed DDPA with a zinc compound. For example, adithiophosphoric acid may be made by reacting mixtures of primary andsecondary alcohols. Alternatively, multiple dithiophosphoric acids canbe prepared where the hydrocarbyl groups on one are entirely secondaryin character and the hydrocarbyl groups on the others are entirelyprimary in character. To make the zinc salt any basic or neutral zinccompound could be used but the oxides, hydroxides and carbonates aremost generally employed. Commercial additives frequently contain anexcess of zinc due to use of an excess of the basic zinc compound in theneutralization reaction.

In one embodiment, however, the lube oil compositions are preferablysubstantially zinc free.

Oxidation inhibitors or antioxidants reduce the tendency of base stocksto deteriorate in service which deterioration can be evidenced by theproducts of oxidation such as sludge and varnish-like deposits on themetal surfaces and by viscosity growth. Such oxidation inhibitorsinclude hindered phenols, alkaline earth metal salts ofalkylphenolthioesters having preferably C₅ to C₁₂ alkyl side chains,calcium nonylphenol sulfide, ashless oil soluble phenates and sulfurizedphenates, phosphosulfurized or sulfurized hydrocarbons, phosphorousesters, metal thiocarbamates, oil-soluble copper compounds as describedin U.S. Pat. No. 4,867,890, and molybdenum containing compounds.

Friction modifiers may be included to improve fuel economy. Oil-solublealkoxylated mono- and di-amines are well known to improve boundary layerlubrication. The amines may be used as such or in the form of an adductor reaction product with a boron compound such as boric oxide, boronhalide, metaborate, boric acid or a mono-, di- or tri-alkyl borate.

Other friction modifiers are known. Among these are esters formed byreacting carboxylic acids and anhydrides with alkanols. Otherconventional friction modifiers generally consist of a polar terminalgroup (e.g. carboxyl or hydroxyl) covalently bonded to an oleophilichydrocarbon chain. Esters of carboxylic acids and anhydrides withalkanols are described in U.S. Pat. No. 4,702,850. An example of anotherconventional friction modifier is organo-metallic molybdenum.

Illustrative rust inhibitors are selected from the group of nonionicpolyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, andanionic alkyl sulfonic acids.

Copper and lead bearing corrosion inhibitors may also be used. Typicallysuch compounds are the thiadiazole polysulfides containing from 5 to 50carbon atoms, their derivatives and polymers thereof. Other additivesare the thio- and polythio-sulfenamides of thiadiazoles such as thosedescribed in UK1560830. Benzotriazole derivatives also fall within thisclass of additives.

An illustrative example of demulsifying component is described inEP-A-0330522. It is obtained by reacting an alkylene oxide with anadduct obtained by reacting a bis-epoxide with a polyhydric alcohol.

Pour point depressants, otherwise known as lube oil improvers, lower theminimum temperature at which the fluid will flow or can be poured. Suchadditives are well known. Typical of those additives which improve thelow temperature fluidity of the fluid are C₈ and C₁₈ dialkylfumarate/vinyl acetate copolymers, polyalkylmethacrylates and the like.

Foam control can be provided by many compounds including an antifoamantof the polysiloxane type, for example, silicone oil or polydimethylsiloxane.

Some of the above-mentioned additives can provide a multiplicity ofeffects; thus, for example, a single additive may act as adispersant-oxidation inhibitor. This approach is well known and does notrequire further elaboration.

Illustrative, non-limiting examples of additives specific to use incompression refrigeration systems follow.

Illustrative extreme pressure and antiwear additives include phosphates,phosphate esters (bicresyl phosphate), phosphites, thiophosphates(zincdiorganodithiophosphates)chlorinated waxes, sulfurized fats and olefins,organic lead compounds, fatty acids, molybdenum complexes, halogensubstituted organosilicon compounds, borates, organic esters, halogensubstituted phosphorous compounds, sulfurized Diels Alder adducts,organic sulfides, compounds containing chlorine and sulfur, metal saltsof organic acids.

Illustrative oxidation and thermal stability improvers includesterically hindered phenols (BHT), aromatic amines, dithiophosphates,phosphites, sulfides and metal salts of dithio acids.

Illustrative corrosion inhibitors include organic acids, organic amines,organic phosphates, organic alcohols, metal sulfonates and organicphosphites.

Viscosity index is the measure of the change in viscosity withtemperature, and a high number suggests that the change in viscositywith temperature is minimal. In view of the high viscosity index of thelube oil compositions of the present invention, it is possible toformulate a lube oil composition which is free of viscosity indeximprover. However, there may be applications where it is desirable tofurther improve viscosity index. Illustrative viscosity index improversinclude polyisobutylene, polymethacrylate and polyalkylstyrenes.

Illustrative pour point and or floc point depressants includepolymethacrylate ethylene-vinyl acetate copolymers, succinamicacid-olefin copolymers, ethylene-alpha olefin copolymers andFriedel-Crafts condensation products of wax with napthalene or phenols.

Illustrative detergents include sulfonates, long-chain alkyl substitutedaromatic sulfonic acids, phosphonates, thiophosphonates, phenolates,metal salts of alkyl phenols, alkyl sulfides, alkylphenol-aldehydecondensation products, metal salts of substituted salicylates,N-substituted oligomers or polymers from the reaction products ofunsaturated anhydrides and amines and co-polymers which incorporatepolyester linkages such as vinyl acetate-maleic anhydride co-polymers.

Illustrative anti-foaming agents are silicone polymers.

Illustrative viscosity adjusters include polyisobutylene,polymethacrylates, polyalkylstyrenes, naphthenic oils, alkylbenzeneoils, paraffinic oils, polyesters, polyvinylchloride and polyphosphates.

In the present invention, the additive(s) should be at least partially(greater than about 50% by weight) miscible in the base stock.Generally, this means that the additives used will be oil soluble atleast to some extent, and preferably to a substantial extent.

The lube oil composition should thus preferably be a substantiallyuniform mixture, with substantially no settling or phase separation ofcomponents.

The lubrication oil composition preferably comprises the additives in anamount of less than 50 wt %, based on the total weight of thelubrication oil composition. In various embodiments, the lubrication oilcan comprise the additives in an amount of about 25 wt % or less, orabout 10 wt % or less, or about 5 wt % or less, based on the totalweight of the lubrication oil composition.

EXAMPLES

All parts, percentages, etc., are by weight unless otherwise indicated.

The number-average molecular weights (Mn) of polyether glycol andpolyether glycol ester were determined either by analyzing end-groupsusing NMR spectroscopic methods or by titration of hydroxyl groups.

ASTM method D445-83 and ASTM method D792-91 were used to determine thekinematic viscosity and density of the polymer, respectively.

Additional ASTM methods were used as listed in the Tables below.

The materials of the present invention were tested with and without alube oil additive package. The package used during the testing comprisedthe components listed in Table 1.

TABLE 1 Additive Description Function Available From IRGALUBE ®Triphenyl phosphorothionate, Anti- Ciba Specialty TPPT typicallycontaining wear/extreme Chemicals, 9% phosphorus pressure Tarrytown, NYand 9.4% sulfur VANLUBE ® Methylene Ashless anti- RT Vanderbilt 7723bis(dibutyldithiocarbamate) oxidant and Company Inc extreme pressureNorwalk, CT VANLUBE ® Tolutriazole antioxidant RT Vanderbilt 887ECompany Inc Norwalk, CT PANA Phenyl anaphthalmine antioxidant Akrochem,Akron OH VANLUBE ® Polymerized 1,2- antioxidant R.T. Vanderbilt RDdihydro-2,2,4- Co., Inc., Norwalk, trimethylquinoline CT IRGANOX ®Hindered phenol antioxidant Ciba Specialty 1135 Chemicals, Tarrytown, NYIRGALUBE ® Mixture of amine EP/AW & corrosion Ciba Specialty 349phosphates inhibitor Chemicals, Tarrytown, NY VANLUBE ® Calciumsulfonate Rust inhibitor RT Vanderbilt 8912E Company Inc Norwalk, CTCUVAN ® 2,5 dimercapto- Corrosion inhibitor & R.T. Vanderbilt 8261,3,4-thiadiazole metal deactivator Co., Inc., derivative Norwalk, CT

Preparation of PO3G Homopolymer—PO3G1

A 22-L, 4-necked, round-bottomed flask, equipped with a nitrogen inlet,and a distillation head was charged with 11877 g of 1,3-propanediol. Theliquid was sparged with nitrogen at a rate of 10 L/min. and mechanicalstirring (using a stirring magnet driven by a magnetic stirrer below theflask) was done for about 15 min. After 15 min., 108 g of sulfuric acidwas slowly added drop-wise from a separatory funnel through one of theports over a period of at least 5 minutes. When this was finished, 15 gof 1,3-propanediol (PDO) was added to the separatory funnel and swirledto remove any residual sulfuric acid. This was added to the flask. Themixture was stirred and sparged as above and heated to 160° C. The waterof reaction was removed by distillation and was collected continuouslyduring the polymerization reaction. The reaction was continued for 25hours, after which it was allowed to cool (while stirring and spargingwere maintained) to 45° C.

The crude material was hydrolyzed as follows. The crude polymer wasadded to a 22-L, 5-necked, round-bottom flask, (equipped with acondenser and a mechanical mixer) along with an equal volume ofdistilled water. This mixture was stirred mechanically, sparged withnitrogen at a rate of about 150 mL/min. and heated to 100° C. It wasallowed to reflux for 4 hours after which the heat was turned off andthe mixture allowed to cool to 45° C. The stirring was discontinued andthe sparging reduced to a minimum. Phase separation occurred duringcooling. The aqueous phase water was removed and discarded. A volume ofdistilled water equal to the initial amount was added to the wet polymerremaining in the flask. Mixing, sparging and heating to 100° C. was doneagain for 1 hour after which the heat was turned off and the materialallowed to cool as before. The aqueous phase was removed and discarded.

The residual sulphuric acid was determined by titration and neutralizedwith an excess of calcium hydroxide. The polymer was dried under reducedpressure at 90° C. for 3 hours and then filtered through a Whatmanfilter paper precoated with a CEL-PURE C-65 filter aid. The resultingPO3G had a number average molecular weight of 940.

Preparation of Poly(trimethylene-Ethylene Ether)Glycol Copolymer—PO3G2

The above procedure described was repeated except for variation in theamounts of 1,3-propanediol (8811.2 g), 1,2-ethanediol (3080.8 g) andsulfuric acid (108 g) to obtain a poly(trimethylene-ethyleneether)glycol copolymer having a number average molecular weight (Mn) of890.

Preparation of a 2-Ethylhexanoate PO3G Ester

1,3-propanediol (2.4 kg, 31.5 moles) was charged into a 5 L flask fittedwith a stirrer, a condenser and an inlet for nitrogen. The liquid in theflask was flushed with dry nitrogen for 30 minutes at room temperatureand then heated to 170° C. while being stirred at 120 rpm. When thetemperature reached 170° C., 12.6 g (0.5 wt %) of concentrated sulfuricacid was added. The reaction was allowed to proceed at 170° C. for 3hours, and then the temperature was raised to 180° C. and held at 180°C. for 135 minutes. A total of 435 mL of distillate was collected. Thereaction mixture was cooled, and then 2.24 kg (14.6 moles) of2-ethylhexanoic acid (99%) was added. The reaction temperature was thenraised to 160° C. under nitrogen flow with continuous agitation at 180rpm and maintained at that temperature for 6 hours. During this periodan additional 305 mL of distillate water was collected. Heating andagitation were stopped and the reaction mixture was allowed to settle.The product was decanted from about 5 g of a lower, immiscibleby-product phase. NMR analysis of the by-product phase confirmed that nocarboxylic acid esters were present.

2.0 kg of the polytrimethylene ether glycol ester product was mixed with0.5 kg of water, and then the resulting mixture was heated at 95° C. for6 hours. The aqueous phase was separated from the polymer phase, andthen the polymer phase was washed twice with 2.0 kg of water. Theresulting product was heated at 120° C. at 200 mTorr to remove volatiles(255 g). The resulting PO3G ester product has the following properties:

Number average molecular weight (Mn)=500

Viscosity at 40° C. and 100° C.=24 and 5.5 cSt, respectively

Viscosity Index (VI)=180

The resulting PO3G ester was analyzed using proton NMR. No peaksassociated with sulfate esters and unreacted 2-ethylhexanoic acid werefound. There was no sulfur detected in the polymer when analyzed usingWDXRF spectroscopy method.

Example 1

PO3G1 (25 wt % based on the weight of the base fluid stock) and the PO3Gester (75 wt % based on the weight of the base fluid stock) preparedabove were mixed and a lube composition was prepared as follows (wt %below based on the total composition weight):

Blend of base fluids 97.3% IRGALUBE ® TPPT 0.40% VANLUBE ® 7723 0.30%VANLUBE ® 887E 0.20% PANA 0.40% VANLUBE ® RD 0.80% IRGALUBE ® 349 0.40%CUVAN ® 826 0.10%Table 2 lists the lube properties of the blend fluid.

TABLE 2 Property ASTM Method Example 2 Viscosity @ 40° C., cSt D445 38.5Viscosity Index 182 Pour point, ° C. D97 0 Flash Point, ° C. D-92 240Evaporation D-972 0.42% Foaming sequence 1, 2, 3 D-892 None Coppercorrosion D-130 1b Four Ball Wear Scar, mm D-4172 0.69 Load Wear IndexD-2783 24.5 Last nonseizure load, (scar, mm) D-2783 40 kg (.31) Lastseizure load (scar, mm) 160 kg (2.59) Weld Load, kg 200 Falex Pin & Vblock Max load, lbs D3233 3400

Example 2

PO3G1 (75 wt % based on the weight of the base fluid stock) and the PO3Gester (25 wt % based on the weight of the base fluid stock) preparedabove were mixed and a lube oil composition was prepared by adding thefollowing additives (wt % below based on the total composition weight):

Blend of base fluids 97.6% TPPT 0.50% PANA 0.50% VANLUBE ® RD 1.00%IRGALUBE ® 349 0.30% CUVAN ® 826 0.10%

Example 3

PO3G2 (75 wt % based on the weight of the base fluid stock) and the PO3Gester (25 wt % based on the weight of the base fluid stock) preparedabove were mixed and a lube oil composition was prepared by adding thefollowing additives (wt % based on total composition weight).

Blend of base fluid 97.60%  IRGALUBE ® TPPT 0.50% PANA 0.50% VANLUBE ®RD 1.00% IRGALUBE ® 349 0.30% CUVAN ® 826 0.10%

Table 3 lists the lube properties of the blend fluid.

Example 4

PO3G2 (25 wt % based on the weight of the base fluid stock) and the PO3Gester (75 wt % based on the weight of the base fluid stock) preparedabove were mixed and a lube oil composition was prepared by adding thefollowing additives (wt % based on total composition weight).

Blend of base fluid 97.60%  IRGALUBE ® TPPT 0.50% PANA 0.50% VANLUBE ®RD 1.00% IRGALUBE ® 349 0.30% CUVAN ® 826 0.10%

Table 3 lists the lube properties of the blend fluid.

TABLE 3 Test Property Method Example 3 Example 4 Four ball wear, mm ASTM0.40 0.63 D-4172 Load wear Index ASTM 33.6 27.2 Last nonseizure loadD-2783  63 kg (0.36 mm)  50 kg (0.33 mm) (scar) Last seizure load (scar)160 kg (2.69 mm) 160 kg (2.68 mm) Weld load 200 kg 200 kg Falex Pin & Vblock test ASTM 4500 4500 Max Load, lbs D-3233

Example 5

A lube oil composition was prepared by adding the following additivepackage to a poly(trimethylene-ethylene ether)glycol (Mn=1100, PO3G3) toform an initial composition.

PO3G3 97.85%  Defoamer DC 200 cSt 0.0025%   VANLUBE ® 7723 0.3%VANLUBE ® 887E 0.4% IRGANOX ® 1135 0.2% IRGALUBE ® TPPT 0.5% IRGALUBE ®349 0.4% VANLUBE ® RD 0.25%  CUVAN ® 826 0.1%

This lube oil composition (90 wt % based on total weight) was blendedwith the 2-Ethylhexanoate PO3G Ester (10 wt % based on total weight)prepared as described above.

Table 4 lists the lube properties of the finished product which issuitable, for example, as a rotating machinery lubricant (gears,bearings) and as a hydraulic fluid.

TABLE 4 Property ASTM Method Viscosity @ 40 C, cSt 236 Viscosity Index206 Pour point, ° C. D97 −45 Flash Point, ° C. D-92 288 Four Ball WearScar, mm D-4172 0.37 Coefficient of friction D-4172 0.033 Load WearIndex D-2783 61.5 Last nonseizure load, D-2783 160 kg (.52) (scar, mm)Weld Load, kg 200 Falex Pin & V block Max D3233 3000 load, lbs OxidationTest Data D4636 Viscosity change, % 24 hrs @ 1.49 190 C. Acid numberchange 0.07 (mg/KOH/g) % Evaporation loss, 0.65 Sediment weight, mg 4.4Copper corrosion D-4646 Dull-ib

1. A lubrication oil composition comprising: (i) a base fluid stockcomprising a mixture of (a) a polytrimethylene ether glycol that is afluid at ambient temperature, and (b) an acid ester of apolytrimethylene ether glycol that is a fluid at ambient temperature,and (ii) one or more lube oil additives.
 2. The lubrication oilcomposition of claim 1, wherein the base fluid stock is about 50 wt % orgreater, based on the total weight of the lubrication oil composition.3. The lubrication oil composition of claim 2, wherein the base fluidstock is about 75 wt % or greater, based on the total weight of thelubrication oil composition.
 4. The lubrication oil composition of claim3, wherein the base fluid stock is about 95 wt % or greater, based onthe total weight of the lubrication oil composition.
 5. The lubricationoil composition of claim 1, wherein the base fluid stock consistsessentially of the mixture of the polytrimethylene ether glycol and theacid ester of the polytrimethylene ether glycol.
 6. The lubrication oilcomposition of claim 1, wherein the weight ratio of the polytrimethyleneether glycol/acid ester of the polytrimethylene ether glycol in the basefluid stock is 1:1 or greater.
 7. The lubrication oil composition ofclaim 1, wherein the weight ratio of the acid ester of thepolytrimethylene ether glycol/polytrimethylene ether glycol in the basefluid stock is 1:1 or greater.
 8. The lubrication oil composition ofclaim 1, wherein the acid ester of the polytrimethylene ether glycolcomprises from about 50 to 100 wt % diester, and from 0 to about 50 wt %monoester, based on the weight of the acid ester.
 9. The lubrication oilcomposition of claim 1, further comprising a lube oil additivecomprising at least one selected from the group consisting of ashlessdispersants, metal detergents, viscosity modifiers, anti-wear agents,antioxidants, friction modifiers, pour point depressants, anti-foamingagents, corrosion inhibitors, demulsifiers and rust inhibitors.
 10. Thelubrication oil composition of claim 1, wherein said lube oil additiveis at least 50% miscible in the base fluid stock.
 11. The lubricationoil composition claim 1, wherein said lube oil composition is asubstantially uniform mixture, with substantially no settling or phaseseparation, of the components.
 12. The lubrication oil composition ofclaim 1, wherein the acid ester of the polytrimethylene ether glycol isan acid ester of a monocarboxylic acid and/or equivalent.
 13. Thelubrication oil composition of claim 12, wherein the monocarboxylic acidhas the formula R—COOH, wherein R is a substituted or unsubstitutedaromatic, aliphatic or cycloaliphatic organic moiety containing from 6to 40 carbon atoms.
 14. The lubrication oil composition of claim 1wherein the acid ester of the polytrimethylene glycol one or morecompounds of the formula (I):

wherein Q represents the residue of a polytrimethylene ether glycolafter abstraction of the hydroxyl groups, R₂ is H or R₃CO, and each ofR₁ and R₃ is individually a substituted or unsubstituted aromatic,saturated aliphatic, unsaturated aliphatic or cyclo-aliphatic organicgroup, containing from 6 to 40 carbon atoms.
 15. The lubrication oilcomposition of claim 1, wherein the acid ester has a number averagemolecular weight based on a polytrimethylene ether glycol having anumber average molecular weight of at least about 250 to less than about10000.
 16. The lubrication oil of claim 1, wherein the polytrimethyleneether glycol has a number average molecular weight of at least about 250to less than about
 10000. 17. The lubrication oil of claim 1, whereinfrom 99% to 100% of repeating units in the polytrimethylene ether glycolare trimethylene ether units.
 18. The lubrication oil of claim 1,wherein the polytrimethylene glycol comprises trimethylene ether unitsand a lesser amount of other polyoxyalkylene ether repeat units.
 19. Thelubrication oil composition of claim 1, wherein the acid ester isprepared from biologically produced 1,3-propane diol.
 20. Thelubrication oil composition of claim 1, wherein the polytrimethyleneether glycol is prepared from biologically produced 1,3-propane diol.21. The lubrication oil composition of claim 1, wherein the acid esterof the polytrimethylene ether glycol has a viscosity that is less thanthe viscosity of the polytrimethylene ether glycol.